LayoutTests/webxr/high-performance.html

<canvas id="a"></canvas>
<canvas id="b"></canvas>
<script>
if (window.testRunner)
    window.testRunner.dumpAsText();

function run()
{
    const out = document.querySelector("p");
    let result = "";

    if (!window.internals) {
        out.innerText = "Test requires internals.";
        return;
    }

    const canvasA = document.getElementById("a");
    const glA = canvasA.getContext("webgl");
    const requested = internals.requestedGPU(glA);
    let defaultValue = "OK";
    if (requested != "default" && requested != "low-power")
        defaultValue = "Unexpected";

    result += `Default: ${defaultValue}<br>`;

    const canvasB = document.getElementById("b");
    const glB = canvasB.getContext("webgl", {xrCompatible: true})

    result += `XR Compatible (should be high-performance): ${internals.requestedGPU(glB)}<br>`;

    out.innerHTML = result;
}

window.addEventListener("load", run, false);
</script>
<p></p>